/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/macros.internal.h"
#include "libc/runtime/memtrack.h"
#include "libc/runtime/runtime.h"

/**
 * Returns true if address isn't stack and was malloc'd or mmap'd.
 *
 * @assume stack addresses are always greater than heap addresses
 * @assume stack memory isn't stored beneath %rsp (-mno-red-zone)
 */
bool isheap(void *p) {
  int x, i;
  uintptr_t rsp;
  asm("mov\t%%rsp,%0" : "=r"(rsp));
  if (ROUNDDOWN(rsp, STACKSIZE) == ROUNDDOWN((intptr_t)p, STACKSIZE)) {
    return false;
  } else {
    if ((intptr_t)p <= (intptr_t)_end) return false;
    x = (intptr_t)p >> 16;
    i = FindMemoryInterval(&_mmi, x);
    return i < _mmi.i && x >= _mmi.p[i].x && x <= _mmi.p[i].y;
  }
}
